KR20160005069A - Method for processing dropped frames and decoder - Google Patents

Abstract

An embodiment of the present invention provides a method and a decoder for processing lost frames. The method comprising: determining a synthesized high frequency band signal of a current lost frame; Determining recovery information corresponding to the current lost frame, the recovery information comprising at least one of a coding mode prior to frame loss, a frame class of a last frame received prior to frame loss, and an amount of consecutively lost frames Wherein the amount of consecutively lost frames is the amount of frames continuously lost until the current lost frame; Determining a global gain gradient of the current lost frame according to the recovery information; Determining a global gain of the current lost frame according to the global gain slope and the global gain of each frame of the previous M frames of the current lost frame; And adjusting a synthesized high frequency band signal of the current lost frame according to a global gain of the current lost frame and a subframe gain of the current lost frame to obtain a high frequency band signal of the current lost frame. The embodiment of the present invention enables the transition of the high frequency band signal of the current lost frame to be natural and smooth, and it is possible to attenuate the noise of the high frequency band signal, thereby improving the quality of the high frequency band signal.

Description

≪ Desc / Clms Page number 1 > METHOD FOR PROCESSING DROPPED FRAMES AND DECODER &

The present application is related to Chinese Patent Application No. 2005-194550 filed with the Chinese Intellectual Property Office on June 16, 2013, entitled " METHOD FOR PROCESSING LOST FRAME, AND DECODER ". 201310297740.1, the contents of which are incorporated herein by reference.

The present invention relates to the field of communications, and more particularly, to a method and a decoder for processing lost frames.

As technology continues to evolve, there is a growing demand for user sound quality. Increasing the negative bandwidth is a major way to improve sound quality. When the information on the added bandwidth is coded in a conventional manner, the bit rate is greatly increased. In this case, the purpose of transmission can not be achieved due to the limitation of the current network bandwidth. Therefore, bandwidth is often increased by using bandwidth extension techniques.

After coding the high frequency band signal using the bandwidth extension technique, the encoder side transmits the coded signal to the decoder side. The decoder side also uses the bandwidth extension technique to recover the high frequency band signal. During signal transmission, frame loss may occur due to network congestion, defects, or other reasons. Since the packet loss rate is an important factor affecting the signal quality, in order to recover the lost frame as accurately as possible in the case of frame loss, a frame loss processing technique has been proposed. In this technique, the decoder uses the synthesized high-frequency band signal of the previous frame as the synthesized high-frequency band signal of the lost frame, and then adjusts the synthesized high-frequency band signal by using the subframe gain and global gain of the current lost frame, . However, in this technique, the subframe gain of the current lost frame is a fixed value and the global gain of the current lost frame is obtained by multiplying the global gain of the previous frame by a fixed gradient, which means that the reconstructed high frequency Resulting in discontinuous transition of the band signal and severe noise in the reconstructed high frequency band signal.

Embodiments of the present invention provide a method and a decoder for processing lost frames, which can improve the quality of a high frequency band signal.

According to a first aspect, there is provided a method of processing a lost frame, the method comprising: determining a composite high frequency band signal of a current lost frame; Determining recovery information corresponding to the current lost frame, the recovery information comprising at least one of a coding mode prior to frame loss, a frame class of a last frame received prior to frame loss, and an amount of consecutively lost frames Wherein the amount of consecutively lost frames is the amount of frames continuously lost until the current lost frame; Determining a global gain gradient of the current lost frame according to the recovery information; Determining a global gain of the current lost frame according to the global gain slope and the global gain of each frame of the previous M frames of the current lost frame, where M is a positive integer; And adjusting a synthesized high frequency band signal of the current lost frame according to a global gain of the current lost frame and a subframe gain of the current lost frame to obtain a high frequency band signal of the current lost frame.

According to a first aspect, in a first possible implementation, the step of determining a global gain slope of the current lost frame in accordance with the recovery information comprises: determining a coding mode of the current lost frame, Coding mode and the amount of consecutively lost frames is determined to be less than or equal to 3, or when the frame class of the current lost frame is the same as the frame class of the last frame received before the frame loss, And determining that the global gain slope is one if the amount of lost frame is determined to be less than or equal to three.

According to a first aspect, in a first possible implementation, the step of determining a global gain slope of the current lost frame in accordance with the recovery information comprises: determining a coding mode of the current lost frame, Or if the frame class of the current lost frame can not be determined to be the same as the frame class of the last frame received before the frame loss, the last frame received before the frame loss is an unvoiced frame or a voiced frame Determining a global gain slope if the frame is a voiced frame and the amount of the continuously lost frame is determined to be less than or equal to 3 and determining that the global gain slope is less than or equal to a predetermined first threshold value, RTI ID = 0.0 > 0. ≪ / RTI >

According to a first aspect, in a third possible implementation, the step of determining a global gain slope of the current lost frame according to the recovery information comprises: determining whether a last frame received before the frame loss is an onset frame of a voiced frame ), Or if it is determined that the last frame received before the frame loss is an audio frame or a silence frame, the global gain slope is determined, and if the global gain slope is greater than a predetermined first threshold . ≪ / RTI >

According to a first aspect, in a fourth possible implementation, determining a global gain slope of the current lost frame according to the recovery information comprises: if the last frame received before the frame loss is an onset frame of the unvoiced frame, Determining the global gain slope and allowing the global gain slope to be less than or equal to a predetermined first threshold value and greater than zero.

With reference to the first aspect or first to fourth possible embodiments of the first aspect, in the fifth possible implementation, the step of determining the subframe gain of the current lost frame comprises the steps of: Determines the subframe gain slope of the current lost frame and determines the subframe gain of the current lost frame according to the subframe gain slope and the subframe gain of each frame of the previous N frames of the current lost frame Step where N is a positive integer.

According to a fifth possible implementation of the first aspect, in a sixth possible implementation, determining a global gain slope of the current lost frame according to the recovery information may comprise: determining a coding mode of the current lost frame based on the frame loss If the last frame received before the frame loss can not be determined to be the same as the coding mode of the last received frame or if the frame class of the current lost frame can not be determined to be the same as the frame class of the last frame received before the frame loss, Frame gain slope is determined to be less than or equal to a predetermined second threshold value and greater than zero, . ≪ / RTI >

In a seventh possible implementation, referring to a fifth possible implementation of the first aspect, the step of determining a global gain slope of the current lost frame according to the recovery information comprises: Frame gain slope, and allowing the subframe gain slope to be greater than a predetermined second threshold value if the subframe gain slope is determined to be an onset frame of the subframe gain slope.

According to a second aspect, there is provided a method of processing a lost frame, the method comprising:

Determining a composite high frequency band signal of the current lost frame; Determining recovery information corresponding to the current lost frame, the recovery information comprising at least one of a coding mode prior to frame loss, a frame class of a last frame received prior to frame loss, and an amount of consecutively lost frames Wherein the amount of consecutively lost frames is the amount of frames continuously lost until the current lost frame; Determining a subframe gain gradient of the current lost frame according to the recovery information; Determining a subframe gain of the current lost frame according to the subframe gain gain and the subframe gain of each frame of the previous N frames of the current lost frame, where N is a positive integer; Determining a global gain of the current lost frame; And adjusting a synthesized high frequency band signal of the current lost frame according to a subframe gain of the current lost frame and a global gain of the current lost frame to obtain a high frequency band signal of the current lost frame.

Referring to a second aspect, in a first possible implementation, determining a subframe gain slope of the current lost frame in accordance with the recovery information may comprise: determining whether the coding mode of the current lost frame is a last frame received before the frame loss Or if the frame class of the current lost frame can not be determined to be the same as the frame class of the last frame received before the frame loss, the last frame received before the frame loss is an unvoiced frame and the consecutively lost Frame gain slope to be less than or equal to a predetermined second threshold value and greater than zero if the amount of the subframe gain slope is determined to be less than or equal to three, .

Referring to a second aspect, in a first possible implementation, determining the subframe gain slope of the current lost frame according to the recovery information may comprise: determining that the last frame received before the frame loss is an onset frame of the unvoiced frame Determining a subframe gain slope, if determined, and allowing the subframe gain slope to be greater than a predetermined second threshold value.

According to a third aspect, a decoder is provided, the decoder comprising: a first determination unit configured to determine a synthesized high frequency band signal of a current lost frame; A second determination unit configured to determine recovery information corresponding to the current lost frame, the recovery information comprising: a coding mode prior to frame loss; a frame class of a last frame received prior to frame loss; Frame, the amount of consecutively lost frames being the amount of frames continuously lost until the current lost frame; A third determination unit configured to determine a global gain slope of the current lost frame according to the recovery information; A fourth determination unit configured to determine a global gain of the current lost frame according to the global gain slope and the global gain of each frame of previous M frames of the current lost frame, where M is a positive integer; And an adjusting unit configured to adjust a synthesized high-frequency band signal of the current lost frame according to a global gain of the current lost frame and a subframe gain of the current lost frame to obtain a high-frequency band signal of the current lost frame .

With reference to a third aspect, in a first possible implementation, the second determination unit is concretely: the coding mode of the current lost frame is the same as the coding mode of the last frame received before the frame loss and the continuously lost If the amount of frames is determined to be less than or equal to 3 or if the frame class of the current lost frame is the same as the frame class of the last frame received before the frame loss and the amount of consecutively lost frames is less than 3 And determines that the global gain slope is 1 when it is determined to be the same.

Referring to the third aspect, in a second possible embodiment, the second determination unit specifically determines whether the coding mode of the current lost frame is the same as the coding mode of the last frame received before the frame loss, Wherein if the last frame received before the frame loss is an unvoiced or voiced frame and the amount of consecutively lost frames is less than 3 if the last frame received before the frame loss can not be determined whether the frame class of the last frame received is equal to the frame class of the last frame received before the frame loss The global gain slope may be less than or equal to a predetermined first threshold value, and may be greater than zero.

With reference to the third aspect, in a third possible implementation, the second determination unit is concretely: if the last frame received before the frame loss is an onset frame of a voiced sound frame, or if the last frame received before the frame loss Audio frame or silent frame, the global gain slope is configured to allow the global gain slope to be greater than a predetermined first threshold value.

Referring to the third aspect, in a fourth possible implementation, the second determination unit specifically determines the global gain slope if it is determined that the last frame received before the frame loss is an onset frame of the unvoiced frame , The global gain slope may be less than or equal to a predetermined first threshold value, and may be greater than zero.

Referring to the first possible embodiment to the fourth possible embodiment of the third aspect or the third aspect, in the fifth possible implementation, the decoder: determines a subframe gain slope of the current lost frame according to the recovery information And determine a subframe gain of the current lost frame according to the subframe gain slope and the subframe gain of each frame of the previous N frames of the current lost frame, Here, N is a positive integer.

With reference to a fifth possible embodiment of the third aspect, in a sixth possible implementation, the fifth decision unit is concretely: the coding mode of the current lost frame is the same as the coding mode of the last frame received before the frame loss Or if the frame class of the current lost frame can not be determined whether it is the same as the frame class of the last frame received before the frame loss, the last frame received before the frame loss is an unvoiced frame and the amount of the continuously lost frame is 3, the subframe gain slope may be less than or equal to a predetermined second threshold value, and may be greater than zero.

With reference to a fifth possible embodiment of the third aspect, in a seventh possible implementation, the fifth decision unit is concretely: when it is determined that the last frame received before the frame loss is an onset frame of the unvoiced frame, Determines a subframe gain slope, and allows the subframe gain slope to be greater than a predetermined second threshold value.

According to a fourth aspect, a decoder is provided, the decoder comprising: a first decision unit configured to determine a synthesized high frequency band signal of a current lost frame; A second determination unit configured to determine recovery information corresponding to the current lost frame, the recovery information comprising: a coding mode prior to frame loss; a frame class of a last frame received prior to frame loss; Frame, the amount of consecutively lost frames being the amount of frames continuously lost until the current lost frame; A third determination unit configured to determine a subframe gain slope of the current lost frame according to the recovery information; A fourth determination unit configured to determine the subframe gain of the current lost frame according to the subframe gain gain and the subframe gain of each frame of the previous N frames of the current lost frame, Integer -; And an adjusting unit configured to adjust a synthesized high-frequency band signal of the current lost frame according to a sub-frame gain of the current lost frame and a global gain of the current lost frame to obtain a high-frequency band signal of the current lost frame .

According to a fourth aspect, in a first possible implementation, the second decision unit is concretely: whether the coding mode of the current lost frame is the same as the coding mode of the last frame received before the frame loss, It is determined that the last frame received before the frame loss is an unvoiced frame and the amount of consecutively lost frames is less than or equal to 3 if the frame class can not be determined whether it is the same as the frame class of the last frame received before the frame loss Frame gain gradient, and the subframe gain slope may be less than or equal to a predetermined second threshold value and may be greater than zero.

According to a fourth aspect, in a second possible implementation, the second decision unit specifically determines the subframe gain slope when it is determined that the last frame received before the frame loss is an onset frame of the unvoiced frame , And the subframe gain slope may be greater than a second predetermined threshold value.

In the embodiment of the present invention, the global gain slope of the current lost frame is determined according to the recovery information, and the global gain of the current lost frame is determined according to the global gain slope and the global gain of each frame of the previous M frames of the current lost frame The synthesized high frequency band signal of the current lost frame is adjusted according to the global gain of the current lost frame and the subframe gain of the current lost frame so that the transition of the high frequency band signal of the current lost frame is smooth and smooth, The noise in the band signal can be attenuated, thereby improving the quality of the high-frequency band signal.

BRIEF DESCRIPTION OF THE DRAWINGS For a better understanding of the technical solution of an embodiment of the present invention, the accompanying drawings, which are needed to illustrate the embodiments of the present invention, are briefly described below. Naturally, the accompanying drawings of the following embodiments are only partial embodiments of the present invention, and those skilled in the art will be able to derive other drawings from the attached drawings without creative effort.
1 is a schematic flow diagram of a method for processing lost frames according to an embodiment of the present invention.
2 is a schematic flow diagram of a method for processing lost frames according to another embodiment of the present invention.
3 is a schematic flow diagram of a process of a method of processing lost frames in accordance with an embodiment of the present invention.
4 is a schematic block diagram of a decoder according to an embodiment of the present invention.
5 is a schematic block diagram of a decoder according to another embodiment of the present invention.
6 is a schematic block diagram of a decoder in an embodiment of the present invention.
7 is a schematic block diagram of a decoder according to another embodiment of the present invention.

Hereinafter, a technical solution of an embodiment of the present invention will be clearly and completely described with reference to the drawings attached to the embodiments of the present invention. Obviously, the described embodiments are only a few of the embodiments of the invention. Any other embodiment that a person skilled in the art acquires based on an embodiment of the present invention without creative effort is within the scope of protection of the present invention.

The coding and decoding techniques are applied to various electronic devices such as a mobile phone, a wireless device, a personal data assistant (PDA), a portable or portable computer, a Global Positioning System (GPS) receiver / Navigator, camera, audio / video player, video camera, video recorder, and monitor device.

To increase voice bandwidth, bandwidth extension techniques are commonly used. Specifically, the encoder side can obtain low frequency band LPC coefficients by coding low frequency band information by using a core-layer encoder and performing linear predictive coding (LPC) analysis on the high frequency band signal. The high-frequency band excitation signal is then obtained according to parameters such as the pitch period, the algebraic codebook, and the gain obtained by the core-layer encoder. After processing the high frequency band excitation signal by the LPC synthesis filter obtained by using the LPC parameter, a synthesized high frequency band signal is obtained. By comparing the original high-frequency band signal and the synthesized high-frequency band signal, the subframe gain and the global gain are obtained. The above-described LPC coefficients are converted into LSF parameters, and LSF parameters, subframe gains, and global gains are quantized and coded. Finally, the bit stream obtained by coding is transmitted to the decoder side.

After receiving the coded bit stream, the decoder side first analyzes the information about the bit stream to determine which stream is lost. If frame loss has not occurred, the bitstream can be decoded normally, and if the frame loss occurs, the decoder side can process the lost frame. A method of processing a lost frame with reference to an embodiment of the present invention will be described in detail below.

1 is a schematic flow diagram of a method for processing lost frames according to an embodiment of the present invention. The method in Fig. 1 is performed on the decoder side.

110: Determines the synthesized high frequency band signal of the current lost frame.

For example, the decoder side may determine the synthesized high frequency band excitation signal of the current lost frame according to the parameters of the previous frame of the current lost frame. Specifically, the decoder side can use the LPC parameters of the previous frame of the current lost frame as the LPC parameters of the current frame and use parameters such as the pitch period, the algebraic codebook, and the gain obtained by the core-layer decoder of the previous frame The high-frequency band excitation signal can be obtained. The decoder side processes the high frequency band excitation signal by using the high frequency band excitation signal as the high frequency band excitation signal of the current lost frame and then using the LPC synthesis filter generated by using the next LPC parameter to generate a synthesized high frequency band Signal can be obtained.

120: determines recovery information corresponding to a current lost frame, the recovery information comprising at least one of a coding mode before frame loss, a frame class of the last frame received before frame loss, and a quantity of consecutively lost frames And the amount of the continuously lost frames is the amount of frames continuously lost until the current lost frame.

The current lost frame is a lost frame which should be processed by the decoder side at present.

The coding loss mode of the frame loss may be a coding mode before the current frame loss event occurs. Generally, to improve coding performance, the encoder side can classify the signal before coding the signal to select the proper coding mode. Currently, the code modes are: an INACTIVE mode, an unvoiced frame coding mode, a voiced sound frame coding mode (VOICED mode), a general frame coding mode (GENERIC mode), a transition frame coding mode (TRANSITION mode) , And an audio frame coding mode (AUDIO mode).

The frame class of the last frame received before the frame loss may be the frame class of the last frame received by the decoder side before the occurrence of the current frame loss event. For example, if the encoder side transmits four frames to the decoder side and the decoder side receives the first frame and the second frame correctly but the third frame and the fourth frame are lost, The frame may be referred to as a second frame. In general, a frame class of a frame may include the following features: (1) a frame (UNVOICED_CLAS frame) having at least one of unvoiced, silent, noise, and voiced endings; (2) a frame of transition from an unvoiced sound to a voiced sound (UNVOICED_TRANSITION frame) if the voiced sound is on or still relatively weak; (3) a transition frame after the voiced sound (VOICED_TRANSITION frame) if the voiced sound characteristics are already very weak; (4) a frame (VOICED_CLAS frame) characterized by a voiced sound when the previous frame of the frame is a voiced sound frame or a voiced onset frame; (5) Onset frame with clear voiced sound (ONSET frame); (6) an onset frame (SIN_ONSET frame) in which harmonics and noise are mixed; And (7) a frame having an inactive characteristic (INACTIVE_CLAS frame). The amount of continuously lost frames is the amount of frames lost consecutively from the current frame loss event to the current lost frame. In essence, the amount of consecutively lost frames can indicate the ranking of the current lost frames in successively lost frames. For example, it is assumed that the encoder side transmits five frames to the decoder side and the decoder side correctly receives the first frame and the second frame, but all of the third frame to the fifth frame are lost. If the current lost frame is the fourth frame, the amount of consecutively lost frames is 2, and if the current lost frame is the fifth frame, the amount of consecutively lost frames is 3.

130: Determines the global gain gradient of the current lost frame according to the recovery information.

140: determines the global gain of the current lost frame according to the global gain slope and the global gain of each frame of the previous M frames of the current lost frame, where M is a positive integer.

For example, the decoder side may weight the global gain of the previous M frames, and then determine the global gain of the current lost frame according to the weighted global gain and global gain slope.

Specifically, the global gain of the current lost frame, FramGain, can be expressed using Equation (1) as:

FramGain = f (?, FramGain (-m)) (1)

Here, FramGain (-m) represents the global gain of the m < th > frame of the previous M frames, and alpha represents the global gain slope of the current lost frame.

For example, the decoder side may determine the global gain FramGain of the current lost frame according to Equation (2) below:

(2)

(2)

이고, wm은 이전의 M개의 프레임에서 m번째 프레임에 대응하는 가중된 값을 나타낼 수 있고, FramGain(-m)은 m번째 프레임의 글로벌 이득을 나타낼 수 있으며, α는 현재 손실 프레임의 글로벌 이득 기울기를 나타낼 수 있다.here

, Wm may represent a weighted value corresponding to the mth frame in the previous M frames, FramGain (-m) may represent the global gain of the mth frame, and alpha is the global gain slope of the current lost frame Lt; / RTI >

It is to be understood that the above example of equation (2) is intended to enable a person skilled in the art to understand the present embodiment better, but not to limit the scope of the present embodiment of the present invention. A person of ordinary skill in the art can make various equivalent modifications or modifications based on Equation (1) to determine various specific expressions of Equation (1), and such modifications or modifications are also within the scope of the present invention.

Generally, to simplify the process of step 130, the decoder side may determine the global gain of the current lost frame according to the global gain and global gain slope of the previous frame of the current lost frame.

150: The high frequency band signal of the current lost frame is obtained by adjusting the synthesized high frequency band signal of the current lost frame according to the global gain of the current lost frame and the subframe gain of the current lost frame.

For example, the decoder side may set the subframe gain of the current lost frame to a fixed value, and the decoder side may determine the subframe gain of the current lost frame in a manner to be described below. The decoder side can then adjust the synthesized high frequency band signal of the current lost frame according to the global gain of the current lost frame and the subframe gain of the current lost frame, thereby obtaining the final high frequency band signal.

In the prior art, the global gain slope of the current lost frame is a fixed value, and the decoder side obtains the global gain of the current lost frame according to the global gain and the fixed global gain slope of the previous frame. Adjusting the synthesized high frequency band signal according to the global gain of the current lost frame obtained by using this method causes discontinuous transition of the final high frequency band signal before and after the frame loss and generates serious noise. However, in this embodiment of the present invention, instead of setting the global gain slope to a fixed value simply, the decoder side can determine the global gain slope according to the recovery information. The recovery information describes the relevant characteristics of the frame loss event, and therefore the global gain slope determined according to the recovery information is more accurate, and accordingly the global gain of the current lost frame is also more accurate. Therefore, the decoder side adjusts the synthesized high frequency signal according to the global gain, so that the transition in the reconstructed high frequency band signal is natural and smooth, the noise in the reconstructed high frequency band signal can be attenuated, The quality of the signal is improved.

In the present embodiment of the present invention, the global gain slope of the current lost frame is determined according to the restoration information, and the global gain of the current lost frame is determined based on the global gain slope and the global value of each frame of the previous M frames of the current lost frame The synthesized high frequency band signal of the current lost frame is adjusted according to the global gain of the current lost frame and the subframe gain of the current lost frame so that the transition in the high frequency band signal of the current lost frame is smooth and smooth And the noise in the high-frequency band signal can be attenuated, thereby improving the quality of the high-frequency band signal.

Alternatively, at step 120, the global gain slope? Described above may be expressed using equation (3): < EMI ID =

alpha = 1.0 - delta * scale (3),

Where delta can represent the adjustment slope of a, the range of values of delta is from 0.5 to 1, and scale can represent the turning amplitude of alpha, indicating the degree to which the current lost frame approaches the previous frame in its current state And the range may be from 0 to 1, where a smaller value may indicate that the energy of the current lost frame is closer to the energy of the previous frame, and the larger the value, the greater the energy of the current lost frame is, Can be shown to be weaker.

Alternatively, as an example, in step 120, the decoder side determines that the coding mode of the current lost frame is the same as the coding mode of the last frame received before frame loss and that the amount of consecutively lost frames is less than or equal to three , Or if the frame class of the current lost frame is equal to the frame class of the last frame received before frame loss and the amount of consecutively lost frames is determined to be less than or equal to 3, then the decoder side has a global gain slope of 1 You can decide.

Specifically, if the decoder side determines that the coding mode of the current lost frame is the same as the coding mode of the last frame received before frame loss and that the amount of consecutively lost frames is less than or equal to 3, If the class is equal to the frame class of the last frame received prior to frame loss and the amount of consecutively lost frames is determined to be less than or equal to 3, then the global gain of the current lost frame may be equal to the global gain of the previous frame , So that alpha can be determined to be 1. For example, in equation (3), the value of delta may be 0.6 and the value of scale may be zero.

Alternatively, in another embodiment, in step 120, it is determined whether the coding mode of the current lost frame is the same as the coding mode of the last frame received before the frame loss, or whether the frame class of the current lost frame is the frame class of the last frame received before the frame loss If it is determined that the last frame received before the frame loss is an unvoiced frame or a voiced frame and the amount of consecutively lost frames is less than or equal to 3, The gain slope may be determined such that the global gain slope may be less than or equal to a predetermined first threshold value and greater than zero.

Specifically, if the coding mode of the current lost frame is the same as the coding mode of the last frame received before frame loss, or if it can not be determined whether the frame class of the current lost frame is the same as the frame class of the last frame received before frame loss, If it is determined that the last frame received before loss is an unvoiced or voiced frame and the amount of consecutively lost frames is less than or equal to 3, then the decoder side can determine that a is a relatively small value, i.e., May be less than the threshold value. For example, the first threshold may be 0.5. For example, in equation (3), the value of delta may be 0.65 and the value of scale may be 0.8.

In the above embodiment, the decoder side determines whether the coding mode of the last frame received before frame loss is the same as the coding mode of the current lost frame or whether the frame class of the last frame received before frame loss is the same as the frame class of the current lost frame May be determined according to the frame class of the last frame received before loss and / or the amount of frames continuously lost. For example, if the amount of consecutively lost frames is less than or equal to 3, then the decoder side may determine that the coding mode of the last received frame is the same as the coding mode of the current lost frame, 3, then the decoder side can determine that the coding mode of the last received frame is the same as the coding mode of the current lost frame. In another example, if the last received frame is the onset frame of the voiced sound frame or the onset frame of the unvoiced frame and the amount of consecutively lost frames is less than or equal to three, then the decoder side determines that the frame class of the current lost frame The decoder side may determine that the coding mode of the last frame received prior to frame loss is the same as the coding mode of the currently lost frame, or if the last received < RTI ID = 0.0 > It can not be determined whether the frame class of the frame is the same as the first class of the current lost frame.

Alternatively, in another embodiment, if it is determined that the last frame received prior to frame loss is an onset frame of a voiced sound frame, or that the last frame received prior to frame loss is an audio frame or a silence frame, The global gain slope may be determined and the global gain slope may be greater than a predetermined first threshold value.

Specifically, if the decoder side determines that the last frame received before the frame loss is an onset frame of the voiced sound frame, it is likely that the current lost frame is determined to be a voiced sound frame, so that a can be determined to be a relatively large value, alpha may be greater than a first threshold value set in advance. For example, in equation (3), the value of delta may be 0.5 and the value of scale may be 0.4.

If the decoder side determines that the last frame received before frame loss is an audio frame or a silent frame, then it may be determined that alpha is a relatively large value, i.e., alpha may be greater than a preset first threshold value. For example, in equation (3), the value of delta may be 90.5 and the value of scale may be 0.4.

Alternatively, in another embodiment, if the last frame received before the frame loss is an onset frame of the unvoiced frame, the decoder side can determine the global gain slope, and if the global gain slope is less than or equal to the predetermined first threshold And can be greater than zero.

If the last frame received before the frame loss is an onset frame of an unvoiced frame, then the current lost frame may be an unvoiced frame, so that the decoder side can determine that a is a relatively small value, i.e., if a is less than a predetermined first threshold . For example, in equation (3), the value of delta may be 0.8 and the value of scale may be 0.65.

Further, in addition to being indicated by the abovementioned recovery information, in other cases, the decoder side may determine that a is a relatively small value, i.e., alpha may be less than a predetermined first threshold value. For example, in equation (3), the value of delta may be 0.8 and the value of scale may be 0.75.

Alternatively, in another embodiment, the value range of the first threshold value described above may be: 0 <first threshold value <1.

Alternatively, in another embodiment, the decoder side may determine the subframe gain slope of the current lost frame according to the recovery information, and determine the subframe gain slope and the subframe gain of each frame of the previous N frames of the current lost frame Frame gain of the current lost frame, where N is a positive integer.

In addition to the decoder side being able to determine the global gain slope of the current lost frame according to the above restoration information, the decoder side may also determine the subframe gain slope of the current lost frame according to the above restoration information. For example, the decoder side may weight the subframe gain of the previous N frames, and then determine the subframe gain of the current lost frame according to the weighted subframe gain and subframe gain slope.

Specifically, the subframe gain SubGain of the current lost frame can be expressed using Equation (4) as follows:

SubGain = f (?, SubGain (-n)) (4)

Denotes the subframe gain of the nth frame of the previous N frames, and [beta] denotes the subframe gain slope of the current lost frame.

For example, the decoder side may determine the subframe gain SubGain of the current lost frame according to Equation (5) below:

이고, wm은 이전의 N개의 프레임에서 n번째 프레임에 대응하는 가중된 값을 나타낼 수 있고, SubGain(-n)은 n번째 프레임의 서브프레임 이득을 나타낼 수 있으며, β는 현재 손실 프레임의 서브프레임 이득 기울기를 나타낼 수 있으며, β의 범위는 1 내지 2일 수 있다.here

, Wm may represent a weighted value corresponding to the nth frame in the previous N frames, SubGain (-n) may represent the subframe gain of the nth frame, A gain slope, and the range of? May be 1 to 2.

It is to be understood that the above example of Equation (5) is intended to enable a person skilled in the art to better understand the present embodiment of the present invention, and not to limit the scope of the present embodiment of the present invention. A person of ordinary skill in the art can make various equivalent modifications or modifications based on Equation (4) to determine various specific expressions of Equation (4), and such variations or modifications are also within the scope of the present invention.

To simplify the process, the decoder side may determine the subframe gain of the current lost frame according to the subframe gain and subframe gain slope of the previous frame of the current lost frame.

As can be seen in this embodiment, instead of simply setting the subframe gain slope of the current lost frame to a fixed value, the subframe gain of the current lost frame is determined after the subframe gain slope is determined according to the restoration information, Therefore, the synthesized high frequency band signal is adjusted according to the subframe gain of the current lost frame and the global gain of the current lost frame, so that the transition in the high frequency band signal of the current lost frame can be natural and smooth, So that the quality of the high-frequency band signal is improved.

Alternatively, in another embodiment, it is determined whether the coding mode of the current lost frame is the same as the coding mode of the last frame received before frame loss, or whether the frame class of the current lost frame is the same as the frame class of the last frame received before frame loss If the last frame received before frame loss is not voiced and the amount of consecutively lost frames is determined to be less than or equal to 3, then the decoder side can determine the subframe gain slope, and if the subframe gain slope is set to a preset And may be less than or equal to the second threshold and greater than zero.

For example, the second threshold may be 1.5 and beta may be 1.25.

Alternatively, in another embodiment, if it is determined that the last frame received before the frame loss is an onset frame of the voiced frame, the decoder side can determine the subframe gain slope, and if the subframe gain slope is greater than a predetermined second threshold Can be made larger.

If the last frame received prior to frame loss is an onset frame of a voiced frame, then the current lost frame is likely to be a voiced frame and the decoder side may determine that? Is a relatively large value, e.g., beta may be 2.0.

In addition to the two cases indicated by the above-described restoration information, in other cases,? May be one in other cases.

Alternatively, in another embodiment, the value range of the second threshold described above may be as follows: 1 < second threshold < 2.

2 is a schematic flow diagram of a method for processing lost frames according to another embodiment of the present invention. The method in Fig. 2 is realized by the decoder side.

210: Determines the synthesized high frequency band signal of the current lost frame.

The decoder side can determine the synthesized high frequency band excitation signal of the lost frame according to the prior art. For example, the decoder side may determine the synthesized high frequency band excitation signal of the current lost frame according to the parameters of the previous frame of the current lost frame. Specifically, the decoder side can use the LPC parameters of the previous frame of the current lost frame as the LPC parameters of the current frame and use parameters such as the pitch period, the algebraic codebook, and the gain obtained by the core-layer decoder of the previous frame The high-frequency band excitation signal can be obtained. The decoder side processes the high frequency band excitation signal by using the high frequency band excitation signal as the high frequency band excitation signal of the current lost frame and then using the LPC synthesis filter generated by using the next LPC parameter to generate a synthesized high frequency band Signal can be obtained.

220: determines recovery information corresponding to a current lost frame, the recovery information comprising at least one of a coding mode before frame loss, a frame class of the last frame received before frame loss, and a quantity of consecutively lost frames And the amount of the continuously lost frames is the amount of frames continuously lost until the current lost frame.

A detailed description of the restoration information will be given with reference to the detailed description in the embodiment of Fig. 1, and will not be described here again.

230: Determines the subframe gain slope of the current lost frame according to the recovery information.

240: determines a subframe gain of the current lost frame according to the subframe gain of each frame of the previous N frames of the current lost frame and the subframe gain slope, where N is a positive integer.

For example, the decoder side may weight the subframe gain of the previous N frames, and then determine the subframe gain of the current lost frame according to the weighted subframe gain and subframe gain slope.

Specifically, the subframe gain SubGain of the current lost frame can be represented by using Equation (4).

For example, the decoder side can determine the subframe gain SubGain of the current lost frame according to equation (5).

It is to be understood that the above example of Equation (5) is intended to enable a person skilled in the art to better understand the present embodiment of the present invention, and not to limit the scope of the present embodiment of the present invention. A person of ordinary skill in the art can make various equivalent modifications or modifications based on Equation (4) to determine various specific expressions of Equation (4), and such variations or modifications are also within the scope of the present invention.

To simplify the process, the decoder side may determine the subframe gain of the current lost frame according to the subframe gain and subframe gain slope of the previous frame of the current lost frame.

250: The high frequency band signal of the current lost frame is obtained by adjusting the synthesized high frequency band signal of the current lost frame according to the subframe gain of the current lost frame and the global gain of the current lost frame.

For example, the decoder side may set the fixed global gain slope according to the prior art, and then determine the global gain of the current lost frame according to the fixed global gain slope and the global gain of the previous frame.

In the prior art, the decoder side sets the subframe gain of the current lost frame to a fixed value and adjusts the synthesized high frequency band signal of the current lost frame according to this fixed value and the global gain of the current lost frame, Causing a discontinuous transition of the high frequency band signal and generating severe noise. However, in the present embodiment of the present invention, the decoder side determines the subframe gain slope in accordance with the restoration information, and then, instead of simply setting the subframe gain of the current lost frame to a fixed value, The subframe gain of the current lost frame can be determined. The recovery information describes the relevant characteristics of the frame loss event, and thus the subframe gain of the current lost frame is more accurate. Therefore, the decoder side adjusts the synthesized high-frequency signal according to the subframe gain, so that the transition in the reconstructed high-frequency band signal is natural and smooth, and the noise in the reconstructed high-frequency band signal can be attenuated, The quality of the band signal is improved.

In this embodiment, the subframe gain slope of the current lost frame is determined according to the recovery information, and the subframe gain of the current lost frame is the subframe gain slope and the subframe gain of the current frame of the previous N frames of the current lost frame The composite high frequency band signal of the current lost frame is adjusted according to the subframe gain of the current lost frame and the global gain of the current lost frame so that the transition in the high frequency band signal of the current lost frame is natural The noise in the high-frequency band signal can be attenuated, thereby improving the quality of the high-frequency band signal.

Alternatively, in another embodiment, if the coding mode of the current lost frame is the same as the coding mode of the last frame received before the frame loss, or if the frame class of the current lost frame is the same as the frame class of the last frame received before the frame loss If the last frame received before the frame loss is an unvoiced frame and it is determined that the amount of consecutively lost frames is less than or equal to 3, then the decoder side can determine the subframe gain slope, and if the subframe gain slope May be less than or equal to a predetermined second threshold value and greater than zero.

For example, the second threshold may be 1.5 and beta may be 1.25.

Alternatively, in another embodiment, if it is determined that the last frame received before frame loss is an onset frame of an unvoiced frame, the decoder side determines a subframe gain slope, and if the subframe gain slope is greater than a second predetermined threshold Can be made large.

If the last frame received prior to frame loss is an onset frame of unvoiced frame, then the current lost frame is likely to be a voiced sound frame, the decoder side is likely to be a voiced sound frame, and the decoder side can determine that? Is a relatively large value, For example, β may be 2.0.

In addition to the two cases indicated by the above-described restoration information, in other cases,? May be one in other cases.

Alternatively, in another embodiment, the value range of the second threshold described above may be as follows: 1 < second threshold < 2.

As can be seen from the foregoing, the decoder side can determine the global gain of the current lost frame according to this embodiment of the present invention and determine the subframe gain of the current lost frame according to the prior art; Or the decoder side may determine the subframe gain of the current lost frame according to this embodiment of the present invention and determine the global gain of the current lost frame according to the prior art; Or the decoder side may determine the subframe gain of the current lost frame and the global gain of the current lost frame according to this embodiment of the present invention. All of the above-described methods can make the transition in the high frequency band signal of the current loss frame natural and smooth, and can attenuate the noise in the high frequency band signal, thereby improving the quality of the high frequency band signal.

3 is a schematic flow diagram of a process of a method of processing lost frames in accordance with an embodiment of the present invention.

301: Analyzes the frame loss flag in the received bitstream.

This process can be carried out according to the prior art.

302: Determines whether the current frame is loss according to the frame loss flag.

If the frame loss flag indicates that the current frame is not lost, step 303 is executed.

If the frame loss flag indicates that the current frame is loss, steps 303 to 306 are executed.

303: If the frame loss flag indicates that the current frame is not lost, it decodes the bit stream and restores the current frame.

If the frame loss flag indicates that the current frame is lost, steps 304 through 306 may be performed simultaneously, or steps 304 through 306 may be performed in a particular order, which is not limiting in this embodiment of the invention.

304: The synthesized high frequency band signal of the current lost frame is determined.

For example, the decoder side may determine the synthesized high frequency band excitation signal of the current lost frame according to the parameters of the previous frame of the current lost frame. Specifically, the decoder side can use the LPC parameters of the previous frame of the current lost frame as the LPC parameters of the current frame and use parameters such as the pitch period, the algebraic codebook, and the gain obtained by the core-layer decoder of the previous frame The high-frequency band excitation signal can be obtained. The decoder side processes the high frequency band excitation signal by using the high frequency band excitation signal as the high frequency band excitation signal of the current lost frame and then using the LPC synthesis filter generated by using the next LPC parameter to generate a synthesized high frequency band Signal can be obtained.

305: Determines the global gain of the current lost frame.

Optionally, the decoder side determines the global gain slope of the current lost frame in the recovery information of the current lost frame, and the recovery information includes the following: a coding mode before frame loss, a frame class of the last frame received before frame loss, , And then determine the global gain of the current lost frame according to the global gain slope of the current lost frame and the global gain of each frame of the previous M frames.

For example, optionally, the decoder side can further determine the global gain of the current lost frame according to the prior art. For example, the global gain of the current lost frame may be obtained by multiplying the global gain of the previous frame by the fixed global gain slope.

306: Determines the subframe gain of the current lost frame.

Alternatively, the decoder side may also determine the subframe gain slope of the current lost frame according to the recovery information of the current lost frame, and then determine the global gain slope of the current lost frame and the subframe gain of each frame of the previous N frames The subframe gain of the current lost frame can be determined.

Optionally, the decoder side may determine the subframe gain of the current lost frame according to the prior art, e.g., set the subframe gain of the current lost frame to a fixed value.

In order to increase the quality of the reconstructed high frequency band signal corresponding to the current lost frame, if the global gain of the current lost frame is determined in step 305 according to the prior art, then in step 306 the subframe gain of the current lost frame is determined It should be determined according to the method in the example. If the global gain of the current lost frame is determined in step 305 using the method in the embodiment of FIG. 1, then in step 306, the subframe gain of the current lost frame may be determined using the method in the embodiment of FIG. 2 , The subframe gain of the current lost frame may be determined according to the prior art.

307: According to the global gain of the current lost frame obtained in step 305 and the subframe gain of the current lost frame obtained in step 306, the synthesized high frequency band signal obtained in step 304 is adjusted to acquire the high frequency band signal of the current lost frame do.

In the present embodiment of the present invention, the global gain slope of the current lost frame is determined according to the restoration information, or the subframe gain slope of the current lost frame is determined according to the restoration information, The combined high frequency band signal of the current lost frame is adjusted according to the global gain of the current lost frame and the subframe gain of the current lost frame so that the transition of the high frequency band signal of the current lost frame is smooth and smooth And the noise in the high-frequency band signal can be attenuated, thereby improving the quality of the high-frequency band signal.

4 is a schematic block diagram of a decoder according to an embodiment of the present invention. An example of the device 400 in FIG. 4 is a decoder. The apparatus 400 includes a first determination unit 410, a second determination unit 420, a third determination unit 430, a fourth determination unit 440, and a coordination unit 450.

The first determination unit 410 determines the synthesized high frequency band signal of the current lost frame. The second determination unit 420 determines recovery information corresponding to the current lost frame, and the recovery information includes the following: a coding mode before frame loss, a frame class of the last frame received before frame loss, Frame, and the amount of consecutively lost frames is the amount of frames that are continuously lost until the current lost frame. The third determination unit 430 determines the global gain slope of the current lost frame according to the recovery information. The fourth decision unit 440 determines the global gain of the current lost frame according to the global gain slope and the global gain of each frame of the previous M frames of the current lost frame, where M is a positive integer. The subframe gain of the current lost frame is determined. The adjustment unit 450 adjusts the synthesized high frequency band signal of the current lost frame according to the global gain of the current lost frame and the subframe gain of the current lost frame to obtain the high frequency band signal of the current lost frame.

In this embodiment of the present invention, the global gain slope of the current lost frame is determined according to the recovery information, and the global gain of the current lost frame is determined by the global gain slope and the global value of each frame of the previous M frames of the current lost frame The synthesized high frequency band signal of the current lost frame is adjusted according to the global gain of the current lost frame and the subframe gain of the current lost frame so that the transition in the high frequency band signal of the current lost frame is smooth and smooth And the noise in the high-frequency band signal can be attenuated, thereby improving the quality of the high-frequency band signal.

Alternatively, as an embodiment, if the coding mode of the current lost frame is equal to the coding mode of the last frame received before the frame loss and the amount of consecutively lost frames is determined to be less than or equal to 3, If the frame class is equal to the frame class of the last frame received before the frame loss and it is determined that the amount of consecutively lost frames is less than or equal to 3, the third determination unit 430 determines that the global gain slope is 1 You can decide.

Alternatively, in another embodiment, it is determined whether the coding mode of the current lost frame is the same as the coding mode of the last frame received before frame loss, or whether the frame class of the current lost frame is the same as the frame class of the last frame received before frame loss If not, if the last frame received before frame loss is an unvoiced or voiced frame and the amount of consecutively lost frames is determined to be less than or equal to 3, the third determination unit 430 may determine the global gain slope , The global gain slope may be less than or equal to a predetermined first threshold value, and may be greater than zero.

Alternatively, in another embodiment, if the last frame received prior to frame loss is an onset frame of a voiced sound frame, or if it is determined that the last frame received before frame loss is an audio frame or a silent frame, then the third determination unit 430 ) May determine a global gain slope and may cause the global gain slope to be greater than a predetermined first threshold value.

Alternatively, in another embodiment, if it is determined that the last frame received before frame loss is an onset frame of the unvoiced frame, the third determination unit 430 may determine a global gain slope, and if the global gain slope is set to a preset And may be less than or equal to the first threshold value and greater than zero.

Alternatively, as another embodiment, a fifth decision unit 450 is further included. The fifth decision unit 450 may determine the subframe gain slope of the current lost frame according to the recovery information. The fifth determining unit 450 may determine the subframe gain of the current lost frame according to the subframe gain of each frame of the previous N frames of the current lost frame and the subframe gain slope, It is a positive integer.

Alternatively, in another embodiment, it is determined whether the coding mode of the current lost frame is the same as the coding mode of the last frame received before frame loss, or whether the frame class of the current lost frame is the same as the frame class of the last frame received before frame loss If not, the fifth decision unit 450 may determine the subframe gain slope if the last frame received before the frame loss is an unvoiced frame and it is determined that the amount of consecutively lost frames is less than or equal to 3, The subframe gain slope may be less than or equal to a preset second threshold value.

Alternatively, in another embodiment, if it is determined that the last frame received before the frame loss is an onset frame of the unvoiced frame, then the fifth decision unit 450 may determine the subframe gain slope and the subframe gain slope And can be made larger than a preset second threshold value.

Regarding other functions and operations of the device 400, reference is made to the method embodiments in Figs. 1 and 3, which are not repeated here.

5 is a schematic block diagram of a decoder according to another embodiment of the present invention. An example of the device 500 in FIG. 5 is a decoder. The apparatus 500 in FIG. 5 includes a first determination unit 510, a second determination unit 520, a third determination unit 530, a fourth determination unit 540, and a coordination unit 550 .

The first determination unit 510 determines the synthesized high frequency band signal of the current lost frame. The second determination unit 520 determines recovery information corresponding to the current lost frame, and the recovery information includes the following: a coding mode before frame loss, a frame class of the last frame received before frame loss, Frame, and the amount of consecutively lost frames is the amount of frames that are continuously lost until the current lost frame. The third determination unit 530 determines the subframe gain slope of the current lost frame according to the recovery information. The fourth decision unit 540 determines the subframe gain of the current lost frame according to the subframe gain of each frame of the previous N frames of the current lost frame and the subframe gain slope, Lt; / RTI &gt; The adjustment unit 540 adjusts the synthesized high frequency band signal of the current lost frame according to the subframe gain of the current lost frame and the global gain of the current lost frame to obtain the high frequency band signal of the current lost frame.

In this embodiment, the global gain slope of the current lost frame is determined according to the restoration information, and the global gain of the current lost frame depends on the global gain slope and the global gain of each frame of the previous M frames of the current lost frame And the synthesized high frequency band signal of the current lost frame is adjusted according to the global gain of the current lost frame and the subframe gain of the current lost frame so that the transition in the high frequency band signal of the current lost frame becomes natural and smooth And the noise in the high frequency band signal can be attenuated, thereby improving the quality of the high frequency band signal.

Alternatively, as an embodiment, it may be determined whether the coding mode of the current lost frame is the same as the coding mode of the last frame received before the frame loss, or whether the frame class of the current lost frame is the same as the frame class of the last frame received before frame loss The third determination unit 530 can determine the subframe gain slope, if the last frame received before the frame loss is an unvoiced frame and the amount of the continuously lost frame is less than or equal to three, And the subframe gain slope may be less than or equal to a preset second threshold value.

Alternatively, in another embodiment, if it is determined that the last frame received before the frame loss is an onset frame of the unvoiced frame, the fourth determination unit 530 may determine the subframe gain slope, and the subframe gain slope And can be made larger than a preset second threshold value.

With respect to other functions and operations of the device 500, reference is made to the method embodiments in Figs. 2 and 3, which are not repeated here.

6 is a schematic block diagram of a decoder in an embodiment of the present invention. An example of the device 600 in FIG. 6 is a decoder. Apparatus 600 includes a memory 610 and a processor 620.

The memory 610 may include a random access memory, a flash memory, a read-only memory, a programmable read-only memory, a non-volatile memory, a register, and the like. The processor 620 may be a central processing unit (CPU).

The memory 610 is configured to store executable instructions. Processor 620 may execute executable instructions stored in memory 610 and determine a synthesized high frequency band signal of the current lost frame; Determining recovery information corresponding to the current lost frame, the recovery information comprising at least one of a coding mode before frame loss, a frame class of the last frame received before frame loss, and a quantity of consecutively lost frames Wherein the amount of consecutively lost frames is the amount of frames continuously lost until the current lost frame; Determine a global gain gradient of the current lost frame according to the recovery information; Determine a global gain of the current lost frame according to the global gain slope and the global gain of each frame of the previous M frames of the current lost frame, where M is a positive integer; And adjusts a synthesized high frequency band signal of the current lost frame according to a global gain of the current lost frame and a subframe gain of the current lost frame to obtain a high frequency band signal of the current lost frame.

In the present embodiment of the present invention, the global gain slope of the current lost frame is determined according to the restoration information, and the global gain of the current lost frame is determined based on the global gain slope and the global value of each frame of the previous M frames of the current lost frame The synthesized high frequency band signal of the current lost frame is adjusted according to the global gain of the current lost frame and the subframe gain of the current lost frame so that the transition in the high frequency band signal of the current lost frame is smooth and smooth And the noise in the high-frequency band signal can be attenuated, thereby improving the quality of the high-frequency band signal.

Alternatively, as an embodiment, if the decoder side determines that the coding mode of the current lost frame is the same as the coding mode of the last frame received before frame loss and the amount of consecutively lost frames is less than or equal to 3, If it is determined that the frame class of the lost frame is equal to the frame class of the last frame received before frame loss and the amount of frames that are continuously lost is less than or equal to 3, the processor 620 determines that the global gain slope is one .

Alternatively, in another embodiment, it is determined whether the coding mode of the current lost frame is the same as the coding mode of the last frame received before frame loss, or whether the frame class of the current lost frame is the same as the frame class of the last frame received before frame loss If not, the processor 620 determines that the decoder side can determine the global gain slope, if the last frame received before the frame loss is an unvoiced or voiced frame and the amount of consecutively lost frames is less than or equal to three, The global gain slope may be less than or equal to a predetermined first threshold value and may be greater than zero.

Alternatively, in another embodiment, if the last frame received prior to frame loss is an onset frame of a voiced sound frame, or if it is determined that the last frame received before frame loss is an audio frame or a silent frame, The gain slope can be determined, and the global gain slope can be made larger than a preset first threshold value.

Alternatively, in another embodiment, if the last frame received before the frame loss is an onset frame of the unvoiced frame, the processor 620 may determine the global gain slope, and if the global gain slope is less than a predetermined first threshold Or equal to, and greater than zero.

Optionally, as another embodiment, the processor 620 may determine the subframe gain slope of the current lost frame according to the recovery information; The subframe gain of the current lost frame may be determined according to the subframe gain of each frame of the previous N frames of the current lost frame, where N is a positive integer.

Alternatively, in another embodiment, it is determined whether the coding mode of the current lost frame is the same as the coding mode of the last frame received before frame loss, or whether the frame class of the current lost frame is the same as the frame class of the last frame received before frame loss If not, the processor 620 may determine the subframe gain slope if it is determined that the last frame received before the frame loss is an unvoiced frame and the amount of consecutively lost frames is less than or equal to three, The gain slope may be less than or equal to a predetermined second threshold value, and may be greater than zero.

Alternatively, in another embodiment, if it is determined that the last frame received before the frame loss is an onset frame of the voiced frame, the processor 620 may determine the subframe gain slope, and if the subframe gain slope 2 &lt; / RTI &gt; threshold value.

With respect to other functions and operations of the apparatus 600, reference is made to the method embodiments in Figs. 1 and 3, which are not repeated here.

7 is a schematic block diagram of a decoder according to another embodiment of the present invention. An example of the apparatus 700 in FIG. 7 is a decoder. The apparatus 700 in FIG. 7 includes a memory 710 and a processor 720.

The memory 710 may include a random access memory, a flash memory, a read-only memory, a programmable read-only memory, a nonvolatile memory, a register, and the like. The processor 720 may be a central processing unit (CPU).

Memory 710 is configured to store executable instructions. Processor 720 may execute executable instructions stored in memory 610 and determine a synthesized high frequency band signal of the current lost frame; Determining recovery information corresponding to the current lost frame, the recovery information comprising at least one of a coding mode before frame loss, a frame class of the last frame received before frame loss, and a quantity of consecutively lost frames Wherein the amount of consecutively lost frames is the amount of frames continuously lost until the current lost frame; Determine a subframe gain slope of the current lost frame according to the recovery information; Frame gain of the current lost frame according to the subframe gain of each frame of the previous N frames of the current lost frame, where N is a positive integer; And adjusts a synthesized high frequency band signal of the current lost frame according to a subframe gain of the current lost frame and a global gain of the current lost frame to obtain a high frequency band signal of the current lost frame.

In this embodiment, the subframe gain slope of the current lost frame is determined according to the recovery information, and the subframe gain of the current lost frame is the subframe gain slope and the subframe gain of the current frame of the previous N frames of the current lost frame The composite high frequency band signal of the current lost frame is adjusted according to the subframe gain of the current lost frame and the global gain of the current lost frame so that the transition in the high frequency band signal of the current lost frame is natural The noise in the high-frequency band signal can be attenuated, thereby improving the quality of the high-frequency band signal.

Alternatively, as an embodiment, it may be determined whether the coding mode of the current lost frame is the same as the coding mode of the last frame received before the frame loss, or whether the frame class of the current lost frame is the same as the frame class of the last frame received before frame loss The processor 720 may determine the subframe gain slope if the last frame received before the frame loss is an unvoiced frame and the amount of consecutively lost frames is less than or equal to three, The slope may be less than or equal to a predetermined second threshold value, and may be greater than zero.

Alternatively, in another embodiment, if it is determined that the last frame received before the frame loss is an onset frame of the unvoiced frame, the processor 720 may determine the subframe gain slope, and if the subframe gain slope 2 &lt; / RTI &gt; threshold value.

With regard to other functions and operations of the apparatus 700, reference is made to the method embodiments in Figs. 2 and 3, which are not repeated here.

Those skilled in the art will appreciate that, in combination with the examples described in the embodiments disclosed herein, unit and algorithm steps may be implemented in electronic hardware or a combination of computer software and electronic hardware. Whether the functions are performed in hardware or software depends on the design constraints of the particular application and technical solution. Those skilled in the art will recognize that other methods may be used to perform the described functions for each particular embodiment, but their implementation should not be interpreted as beyond the scope of the present invention.

It will be appreciated by those skilled in the art that for the convenience and simplicity of explanation, detailed processing of the above described systems, devices, and units may be understood by reference to the corresponding process of the above-described method embodiments, I never do that.

It goes without saying that, in the several embodiments provided in this application, the above-described systems, apparatuses, and methods may be realized in other ways. For example, the described apparatus embodiments are illustrative only. For example, the partitioning of a unit is merely a sort of logical functional partition, and may be in a different partitioning scheme during actual execution. For example, multiple units or components may be combined or integrated into different systems, or some features may be disregarded or not performed. Further, mutual coupling or direct coupling or communication connection shown or discussed may be realized through some interface. Direct coupling or communication connections between devices or units may be realized in electronic, mechanical or other forms.

The units described as separate portions may or may not be physically separate, and the portions depicted as units may or may not be physical units, may be located at one location, and may be distributed to a plurality of network units . Some or all of the units may be selected according to actual needs to achieve the object of the solution of the embodiment.

Further, the functional units in the embodiment of the present invention may be integrated into one processing unit, or each unit may physically exist alone, or two or more units may be integrated into one unit. The integrated unit may be implemented in the form of hardware or in the form of a software functional unit.

Further, the functional units in the embodiment of the present invention may be integrated into one processing unit, each unit may be physically independent, and two or more units may be integrated into one unit.

If the integrated unit is realized in the form of a software functional unit and is marketed or used as a stand-alone product, then this integrated unit can be stored in a computer-readable storage medium. Based on this understanding, essential technical solutions of the present invention, or portions contributing to the prior art, or parts of technical solutions, can be realized in the form of software products. The computer software product is stored on a storage medium and can be a computer software product (which may be a personal computer, a server, a network device, or the like) to perform some or all of the steps of the method described in the embodiments of the present invention. Lt; / RTI &gt; commands. The above-mentioned storage medium includes: a storage medium such as a USB flash disk, a portable hard disk, a read-only memory (ROM), a random access memory (RAM), a magnetic disk or an optical disk do.

The foregoing description is only a specific implementation of the present invention and is not intended to limit the scope of protection of the present invention. All modifications or substitutions easily realized by those skilled in the art within the technical scope described in the present invention are within the scope of protection of the present invention. Therefore, the scope of protection of the present invention is within the scope of the claims.

Claims (22)

CLAIMS 1. A method for processing lost frames,
Determining a composite high frequency band signal of the current lost frame;
Determining recovery information corresponding to the current lost frame, the recovery information comprising at least one of a coding mode prior to frame loss, a frame class of a last frame received prior to frame loss, and an amount of consecutively lost frames Wherein the amount of consecutively lost frames is the amount of frames continuously lost until the current lost frame;
Determining a global gain gradient of the current lost frame according to the recovery information;
Determining a global gain of the current lost frame according to the global gain slope and the global gain of each frame of the previous M frames of the current lost frame, where M is a positive integer; And
Adjusting a synthesized high frequency band signal of the current lost frame according to a global gain of the current lost frame and a subframe gain of the current lost frame to obtain a high frequency band signal of the current lost frame
&Lt; / RTI &gt; The method according to claim 1,
Wherein determining the global gain slope of the current lost frame according to the recovery information comprises:
If the coding mode of the current lost frame is the same as the coding mode of the last frame received before the frame loss and the amount of the continuously lost frames is determined to be less than or equal to 3, Determining that the global gain slope is equal to the frame class of the last frame received before the frame loss and if the amount of the continuously lost frame is determined to be less than or equal to 3
/ RTI &gt; of the lost frame. The method according to claim 1,
Wherein determining the global gain slope of the current lost frame according to the recovery information comprises:
If the coding mode of the current lost frame is the same as the coding mode of the last frame received before the frame loss or if it can not be determined whether the frame class of the current lost frame is the same as the frame class of the last frame received before the frame loss, Determining the global gain slope if the last frame received before the frame loss is an unvoiced frame or a voiced frame and the amount of the continuously lost frame is determined to be less than or equal to 3, Allowing the global gain slope to be less than or equal to a predetermined first threshold value and greater than zero
/ RTI &gt; of the lost frame. The method according to claim 1,
Wherein determining the global gain slope of the current lost frame according to the recovery information comprises:
If it is determined that the last frame received before the frame loss is an onset frame of a voiced sound frame or that the last frame received before the frame loss is an audio frame or a silence frame, And allowing the global gain slope to be greater than a preset first threshold value,
/ RTI &gt; of the lost frame. The method according to claim 1,
Wherein determining the global gain slope of the current lost frame according to the recovery information comprises:
Determining the global gain slope if the last frame received before the frame loss is an onset frame of an unvoiced frame, and allowing the global gain slope to be less than or equal to a predetermined first threshold value and greater than zero
/ RTI &gt; of the lost frame. 6. The method according to any one of claims 1 to 5,
Determining a subframe gain slope of the current lost frame according to the recovery information, and determining a subframe gain slope of the current lost frame according to the subframe gain of each frame of the previous N frames of the current lost frame, The step of determining the gain
, Wherein N is a positive integer. The method according to claim 6,
Wherein determining the global gain slope of the current lost frame according to the recovery information comprises:
If the coding mode of the current lost frame is the same as the coding mode of the last frame received before the frame loss or if it can not be determined whether the frame class of the current lost frame is the same as the frame class of the last frame received before the frame loss, Determining a subframe gain slope if the last frame received before the frame loss is an unvoiced frame and the amount of the continuously lost frame is determined to be less than or equal to 3, &Lt; / RTI &gt; and may be greater than zero
/ RTI &gt; of the lost frame. The method according to claim 6,
Wherein determining the global gain slope of the current lost frame according to the recovery information comprises:
Determining a subframe gain slope if the last frame received prior to the frame loss is determined to be an onset frame of a voiced sound frame, and allowing the subframe gain slope to be greater than a predetermined second threshold value
/ RTI &gt; of the lost frame. CLAIMS 1. A method for processing lost frames,
Determining a composite high frequency band signal of the current lost frame;
Determining recovery information corresponding to the current lost frame, the recovery information comprising at least one of a coding mode prior to frame loss, a frame class of a last frame received prior to frame loss, and an amount of consecutively lost frames Wherein the amount of consecutively lost frames is the amount of frames continuously lost until the current lost frame;
Determining a subframe gain gradient of the current lost frame according to the recovery information;
Determining a subframe gain of the current lost frame according to the subframe gain gain and the subframe gain of each frame of the previous N frames of the current lost frame, where N is a positive integer;
Determining a global gain of the current lost frame; And
Adjusting a synthesized high frequency band signal of the current lost frame according to a subframe gain of the current lost frame and a global gain of the current lost frame to obtain a high frequency band signal of the current lost frame
&Lt; / RTI &gt; 10. The method of claim 9,
Wherein determining the subframe gain slope of the current lost frame according to the recovery information comprises:
If the coding mode of the current lost frame is the same as the coding mode of the last frame received before the frame loss or if it can not be determined whether the frame class of the current lost frame is the same as the frame class of the last frame received before the frame loss, Determining a subframe gain slope if the last frame received before the frame loss is an unvoiced frame and the amount of the continuously lost frame is determined to be less than or equal to 3, &Lt; / RTI &gt; and may be greater than zero
/ RTI &gt; of the lost frame. 10. The method of claim 9,
Wherein determining the subframe gain slope of the current lost frame according to the recovery information comprises:
Determining a subframe gain slope if the last frame received before the frame loss is determined to be an onset frame of the unvoiced frame, and allowing the subframe gain slope to be greater than a second predetermined threshold value
/ RTI &gt; of the lost frame. As a decoder,
A first determination unit configured to determine a synthesized high-frequency band signal of a current lost frame;
A second determination unit configured to determine recovery information corresponding to the current lost frame, the recovery information comprising: a coding mode prior to frame loss; a frame class of a last frame received prior to frame loss; Frame, the amount of consecutively lost frames being the amount of frames continuously lost until the current lost frame;
A third determination unit configured to determine a global gain slope of the current lost frame according to the recovery information;
A fourth determination unit configured to determine a global gain of the current lost frame according to the global gain slope and the global gain of each frame of previous M frames of the current lost frame, where M is a positive integer; And
And an adjustment unit configured to adjust the synthesized high-frequency band signal of the current lost frame according to a global gain of the current lost frame and a subframe gain of the current lost frame to obtain a high-
&Lt; / RTI &gt; 13. The method of claim 12,
The second determination unit may be configured such that when the coding mode of the current lost frame is equal to the coding mode of the last frame received before the frame loss and the amount of the continuously lost frame is less than or equal to 3, Or when the frame class of the current lost frame is equal to the frame class of the last frame received before the frame loss and the amount of the continuously lost frame is determined to be less than or equal to 3, Wherein the decoder is configured to determine the decoder. 13. The method of claim 12,
Specifically, the second determination unit determines whether the coding mode of the current lost frame is the same as the coding mode of the last frame received before the frame loss, or whether the frame class of the current lost frame is the frame of the last frame received before the frame loss Determining whether the last frame received before the frame loss is an unvoiced frame or a voiced frame and the amount of the continuously lost frame is less than or equal to 3, Wherein the global gain slope is configured to be less than or equal to a predetermined first threshold value and greater than zero. 13. The method of claim 12,
The second determination unit specifically determines if the last frame received before the frame loss is an onset frame of a voiced sound frame or if it is determined that the last frame received before the frame loss is an audio frame or a silent frame, Wherein the global gain slope is configured to determine a slope and allow the global gain slope to be greater than a predetermined first threshold value. 13. The method of claim 12,
The second determination unit specifically determines the global gain slope when it is determined that the last frame received before the frame loss is an onset frame of the unvoiced frame, and wherein the global gain slope is less than a predetermined first threshold Or equal to, and greater than zero. 17. The method according to any one of claims 12 to 16,
Determining a subframe gain slope of the current lost frame according to the recovery information, and determining a subframe gain slope of the current lost frame according to the subframe gain of each frame of the previous N frames of the current lost frame, A fifth determination unit configured to determine a gain,
, Wherein N is a positive integer. 18. The method of claim 17,
The fifth determination unit may be configured such that the coding mode of the current lost frame is the same as the coding mode of the last frame received before the frame loss or the frame class of the current lost frame is the frame of the last frame received before the frame loss Frame, determining if the last frame received before the frame loss is an unvoiced frame and the amount of consecutively lost frames is less than or equal to three, determining the sub-frame gain slope, Wherein the frame gain slope is configured to be less than or equal to a predetermined second threshold value and greater than zero. 18. The method of claim 17,
The fifth determining unit determines the subframe gain slope when the final frame received before the frame loss is determined to be an onset frame of the unvoiced frame, and if the subframe gain slope is greater than or equal to a second predetermined threshold value And to be larger than the first decoder. As a decoder,
A first determination unit configured to determine a synthesized high-frequency band signal of a current lost frame;
A second determination unit configured to determine recovery information corresponding to the current lost frame, the recovery information comprising: a coding mode prior to frame loss; a frame class of a last frame received prior to frame loss; Frame, the amount of consecutively lost frames being the amount of frames continuously lost until the current lost frame;
A third determination unit configured to determine a subframe gain slope of the current lost frame according to the recovery information;
A fourth determination unit configured to determine the subframe gain of the current lost frame according to the subframe gain gain and the subframe gain of each frame of the previous N frames of the current lost frame, Integer -; And
Wherein the adjustment unit adjusts the synthesized high frequency band signal of the current lost frame according to the subframe gain of the current lost frame and the global gain of the current lost frame to obtain a high frequency band signal of the current lost frame
&Lt; / RTI &gt; 21. The method of claim 20,
Specifically, the second determination unit determines whether the coding mode of the current lost frame is the same as the coding mode of the last frame received before the frame loss, or whether the frame class of the current lost frame is the frame of the last frame received before the frame loss Frame, determining if the last frame received before the frame loss is an unvoiced frame and the amount of consecutively lost frames is less than or equal to three, determining the sub-frame gain slope, Wherein the frame gain slope is configured to be less than or equal to a predetermined second threshold value and greater than zero. 21. The method of claim 20,
The second determination unit determines the subframe gain slope if the last frame received before the frame loss is determined to be an onset frame of the unvoiced frame, and if the subframe gain slope is greater than a second predetermined threshold And to be larger than the first decoder.

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